But researchers from the Royal Free Medical School and University College London found that people taking quinine for more than a year were 25 per cent more than likely to die early than those not taking the drug.

*Rivaroxaban reduces chances of death by 22% when taken with aspirin

Doctors have warned that a medicine that is prescribed to hundreds of thousands of people who suffer with cramp and restless legs could put them at risk of potentially fatal heart problems.

Quinine, best known for being added to drinks such as tonic water and bitter lemon, was originally used as an anti-malarial drug before being replaced by modern alternatives. It is often given for muscle discomfort, which alongside cramps includes restless leg syndrome – a common condition of the nervous system that causes an irresistible urge to move the legs, or an unpleasant crawling or creeping sensation in the feet, calves and thighs.

But researchers from the Royal Free Medical School and University College London found that people taking quinine for more than a year were 25 per cent more than likely to die early than those not taking the drug.

They believe it may have an effect by itself or interact with other drugs patients are taking, such as the heart-failure drug digoxin and certain statins, all officially listed as causing interactions with quinine. The new study, published in the Journal Of The American Medical Association, adds to mounting evidence of the dangers of quinine. The American Food and Drug Administration previously blamed the drug for 665 adverse events and 93 deaths.

Study author Irwin Nazareth, a Professor of Primary Care at University College London, said: “Many patients are on multiple medications and adding in quinine could present problems.”

The drug is known to cause abnormal heart rhythm in some patients, which can trigger heart attacks. It is also known to affect clotting and may cause a heart attack or stroke by causing an artery to become blocked.

Also, a “phenomenal” pill taken twice a day could protect millions of heart disease patients from an early grave.Rivaroxaban slashes the risk of dying from the world’s leading killer by 22 per cent when taken with aspirin, research has found.

In clinical experiments, the tablet, which is already used for other cardiovascular problems, also reduced strokes by 42 per cent.The “ground-breaking” trial, based on 27,000 patients from 33 countries, has since been halted – 12 months ahead of schedule.

Dr. Derek Connolly, a heart consultant at Birmingham City Hospital, United Kingdom (UK), who was involved in the global study, welcomed the breakthrough. The findings were published in The New England Journal of Medicine.

Scientists split the participants, who all suffered from coronary or peripheral artery disease (CAD/PAD), into three groups.Some patients were given two 2.5mg doses of rivaroxaban, others were given the same alongside 100mg of aspirin.

A third group was just given the aspirin. What did the researchers find? The combination reduced the risk of heart attack and stroke deaths by 22 per cent in patients whose condition was stable.

What is this drug? Rivaroxaban is a blood-thinning drug, which is already an option for atrial fibrillation patients.Previous research has shown it to be less risky than aspirin – which has previously been found to double the risk of heart attacks and bleeding.

In the new COMPASS trial, the risk of major bleeding was higher in the patients who were given the combination treatment.Other notable side effects can include abdominal pain, headaches, nausea and rashes. It can also lead to dry mouth and an abnormally fast heart rate.